I.
The idea that ethics is the province of religion lingers even in relatively secular societies. On a recent Saturday morning, the principal news radio station in Berlin reported a dilemma facing German politicians as they attempt to craft educational policy: children must be required to take classes in religion, or their ethical education will inevitably be neglected. Yet the connection presupposed by the politicians has often been questioned. From Plato on, most philosophers have denied the possibility that the will of a deity could have anything to do with what is required of us. Although philosophy has shaped the ethical teachings of the main Western religions, many of the most influential ethical thinkers have been dedicated to explaining and defending principles in ways that are entirely independent of religious doctrine. If the puzzled politicians had been aware of their own rich intellectual tradition, they would have found easy ways of resolving their dilemma.

For over two millennia, philosophical ventures in moral theory have left their mark on everyday thought and on concepts taken for granted in social and political life. Plato and Aristotle, Hume and Adam Smith, Kant and Hegel, Bentham and Mill have shaped the lives of people who would not recognize their names, people who make claims about virtue and vice, duty and obligation, the proper form of a market economy, and the appropriate sphere of legal protection. Nor does the influence end in the late nineteenth century. G.E. Moore’s assertion that human relationships and beautiful things are the sources of intrinsic value inspired members of the Bloomsbury circle as they attempted to free themselves from the claustrophobia induced by Victorian morality. More recently, John Rawls and Amartya Sen have explored new directions for social and political theory, and Peter Singer has raised serious questions about our treatment of other animals and about the responsibilities of the affluent few toward the many people who live in acute poverty. Even in an age in which the relevance of philosophy to any aspect of culture beyond its own arcane discussions is frequently (and justifiably) questioned, ethical theory would seem to be one area in which philosophers still have important things to contribute.

At the heart of ethical theory are issues that seem inescapable, and that no other field of inquiry promises to answer. How ought we to act? What kinds of things are worth wanting? What type of person should you aspire to be? Many religious people suppose that there is an authoritative source of answers to these questions. They are not moved by Plato’s cogent proof that the will of a being, however powerful, could not ground any moral duty. Nor are they persuaded by Kant’s further development of the same theme: moral reliance on the commands of another presupposes that the commander is not only powerful but also good; hence those who obey must already have standards of goodness and be able to apply them to the commander. After the twentieth century, and the many who attempted to absolve themselves on the grounds that they were only following the Leader’s orders, this Kantian point would seem especially forceful. Still, even those who continue to rely on religious authority should at the very least concede that their preferred manual of ethical instruction is profoundly incomplete. They, too, need ways of guiding their conduct when their decisions lie beyond the scope of the commandments. They might benefit, as generations of religious scholars and teachers before them have done, from the insights of philosophy.

Besides the straightforward questions about the actions, wants, and ideals of personhood, ethical theory often ventures into higher-order issues, seeking to understand the character of ethics itself. Rather than being a desertion of the more pressing problems in favor of academic theorizing, this trend could reasonably be viewed as part of a strategy for discharging ethical theory’s central task. Asking how we might make sense of ethical truth and ethical knowledge, or answering the nihilist who denies that anything matters, can be a valuable initial step toward discovering what ought to be done or what is worth cherishing. Still, as in any field of inquiry, aspiring theorists should beware lest they lose all contact with the questions that provoked the line of investigation they are supposed to be continuing. Thoughtful people who turn to the “literature” in recent ethical theory may well be puzzled by the lack of connection to the practical decisions and difficulties of contemporary life, and they may harbor a suspicion (perhaps more than a suspicion) that ethical theory has become an academic game of dubious relevance.

Derek Parfit is rightly admired for the acuteness of his philosophical intelligence and his dedication to a thorough exploration of the questions he takes up. His first book, Reasons and Persons, which appeared in 1984, was widely viewed as an outstanding contribution to a cluster of questions in metaphysics and ethics, although its crowning achievement was, I think, its fourth part, in which he offered a penetrating series of arguments about the aggregation of value: how should we compare a state in which some number of people enjoy lives of high quality with a state in which considerably more people live at a slightly less exalted level? Questions such as this one bear on topics in welfare economics and social choice theory (although Parfit does not make the connection explicitly). Since he has done so much to shape the character of contemporary ethical theory—particularly by introducing concepts and methods now central to academic philosophical ethics—Parfit’s new book has been eagerly anticipated. Moreover, its sheer size—the two volumes of On What Matters comprise 1,365 pages—invites the thought that this is a magnum opus, a book that might do in our times what Moore accomplished a century ago, or what Kant achieved in the German Enlightenment—though both of them with many fewer pages.

One prediction is almost undeniable. On What Matters will be the subject of innumerable graduate seminars, a book to be pored over for weeks and months by apprentice philosophers and their mentors, a source for journal articles that will refine a principle here or challenge an argument there. It will be a paradigm in the original, uncorrupted sense of the word, one that will give rise to a professional practice of philosophizing. But will it—or should it—have an impact on broader cultural discussions, shaping future thoughts about what we ought to do or want or aspire to become?

II.
It is a virtue of Parfit’s book that it aims to cover the traditional domain of ethical theory. Its discussions of questions about the character and status of ethics are integrated with substantive conclusions about which actions are right or wrong, and which desires are worth having. Parfit opposes nihilists (who think that nothing matters), social relativists (who suppose that what matters depends on society), and subjectivists (who claim that what matters is a function of what people want). In the terms that he favors, there are objective standards for “what we have most reason” to want and to do: the awfulness of pain, for example, gives us an objective reason to avoid being in agony. It is not at all evident, however, that posing the issues in terms of “reasons” is particularly helpful, or that the question of “what we have most reason to do” is an improvement on asking, “what, all things considered, ought we to do,” because the notion of “something’s being a reason for someone” remains elusive and obscure, despite Parfit’s many attempts to get it clear and right.

In any case, Parfit’s central task, undertaken in the first volume, is to think systematically about these objective reasons and to formulate a “supreme principle of morality.” This is an enterprise in which he takes himself to be continuing the philosophical tradition, particularly as exemplified by his “heroes” Kant and Sidgwick. (The latter’s Methods of Ethics—a “great, drab book,” in Parfit’s words—developed the utilitarianism of Bentham and Mill in ways that absorb ideas from rival traditions.) On the face of it, the thought that morality should have a “supreme principle” is puzzling, for it is not obvious that our ethical life can be subsumed under any single formula. Some people worry about the idea that physical theory can be distilled into some mighty equation, taken to be the core of a “theory of everything,” but the field of ethics appears even less susceptible to such spectacular unification. If ten commandments are unable to suffice, how can we hope to manage with one?

Many of Parfit’s remarks indicate that he thinks of ethical theorizing as analogous to what occurs in theoretical science, but his conception of a “supreme principle” is more subtle and more promising. As we learn when he begins to entertain serious candidates for the role, the fundamental law of ethical theory is to be framed in ways that facilitate its application to human decisions: “The Kantian Contractualist Formula: Everyone ought to follow the principles whose universal acceptance everyone could rationally will. This formula might be what Kant was trying to find: the supreme principle of morality.” Like several of the ideas proposed in Kant’s seminal Foundations of the Metaphysics of Morality, Parfit’s formula attains great generality by offering a test someone might apply in making a decision of any sort.

Later, in the second volume, Parfit makes it clear that his unified theory of ethics is not supposed to decide every ethical issue. He does not believe that all ethical questions have determinate answers. In this regard he cites issues about “the ethics of population or the morality of war.” For this reason, whatever tests are enjoined by the “supreme principle” may not always be applicable: the task, presumably, is to supply criteria adequate for resolving only the ethical questions that are in principle answerable.

The central claim of On What Matters is Parfit’s proposal of the “Triple Theory.” It attempts to characterize the wrongness of acts.

An act is wrong if and only if, or just when, such acts are disallowed by some principle that is

(1) one of the principles whose being universal laws would make things go best,

(2) one of the only principles whose being universal laws everyone could rationally will....

(3) a principle that no one could reasonably reject.

Plainly, these formulations involve concepts about which many readers (and many philosophers) may doubt their own fluency; and Parfit devotes pages, sections, and entire chapters to attempts to explain some of these concepts. Even in advance of working through his discussions, however, his statement of the Triple Theory brings out the structure of his ideas. Although the characterization of wrongness appears to involve three different tests, he claims that the three criteria give the same results—acts debarred by one would be ruled out by the other two. The point of exploring and offering all three is to reveal an unexpected convergence among three major traditions in moral thought. In an image he employs repeatedly, the history of ethical theory is described as a series of attempts to climb a mountain from different sides—and now that we are closer to the peak, it is possible to recognize that these are attempts on the same mountain and that the routes are coming together.

The three traditions of thought whose convergence Parfit wishes to affirm are consequentialism, Kantianism, and contractualism. Consequentialists begin from the idea that some states of affairs are better or worse than others, and construe right actions as those tending to produce outcomes that are as good as possible. The version of consequentialism favored by Parfit is one that focuses on general principles rather than specific actions: instead of declaring that an action is right if it generates the best results, he understands right actions as those commended by rules, or “universal laws,” that “make things go best.” Kantians suppose that the principles of morality are those that could rationally be willed to hold as universal laws—or, to come closer to one of Kant’s original formulations, those laws that would be agreed upon for their self-governance by a community of rational beings. And contractualists suppose that the principles of morality are those that would be agreed on in a discussion under some type of ideal conditions.

Much of the work in the first volume of On What Matters consists in efforts to make some of the central notions of these three traditions clear and precise, and, on that basis, to formulate the most defensible version of each. And after Parfit has argued that the principles are equivalent, we are supposed to conclude that this unexpected convergence of approaches often viewed as starkly incompatible redounds to the credit of the Triple Theory, and that Parfit’s—and moral philosophy’s—work is done.

WHY, THEN, is there a second volume, still longer than the first? Partly because of an accidental feature: an earlier and shorter version of Parfit’s ideas was presented as a set of Tanner Lectures at Berkeley, and, by the conditions of those lectures, publication of a developed version should be accompanied by the discussions of distinguished commentators and the replies of the lecturer. Thus the second volume opens with a different set of voices, three belonging to the original discussants (Susan Wolf, Allen Wood, and T.M. Scanlon) and one subsequently recruited (Barbara Herman). But after 250 pages of such exchanges, the bulk of the volume is then devoted to Parfit’s attempt to explain the status of ethics. He hopes to demolish a threatening view—he calls it Naturalism—according to which the only facts are natural facts: the world contains only those things that would be described by improved versions of the full range of human, natural, and social sciences, and philosophers should dream of no more things than there are in heaven and Earth. For Naturalists, ethics either turns out to be concerned with a certain type of natural fact, or it fails as a correct description of anything. Parfit devotes great energy to distinguishing many different forms of the Naturalist idea, arguing that all are incorrect, and then offers his own preferred account of what ethics is about (it delivers a species of “non-ontological truth”) and how we can know ethical truths (we have a special ability, about which little can be said, that acquaints us with these truths). All this takes time.

A bare survey of the principal contours of On What Matters fosters the impression that it is a leisurely book, one that did not need to swell to its exceptional length. Such a judgment would be unwarranted. Parfit’s book is noteworthy for the density of its argumentation. At almost every paragraph, readers who want to achieve a firm grip on the thoughts that he is developing will have to pause and to ponder. This is partly a matter of the difficulty of the notions that Parfit is trying to make precise, and partly a tribute to his honesty in considering alternatives and pursuing them doggedly. Yet it is also the result of the method that Parfit favors, one now prominent in ethical theory as a result of his influence.

In hundreds of staccato paragraphs, we start with some candidate principle, confront it with a story about some artificially simplified situation, announce a judgment about the way to appraise that situation, and render a verdict on the status of the principle. Many of the stories involve schematically described predicaments in which people are in danger of bodily damage or of death: trapped on rocks or by an earthquake, or lying tied to a railroad track in a tunnel (with possibilities for someone to divert an oncoming train, thereby sending it on a track through a different tunnel where some lesser number of people are bound—or even for someone to have the option of pitching a bystander from a bridge above the track, so that the train will be stopped by his body). Under the names assigned to them, these exercises in moral fiction recur throughout the web of argument. Here is an example of the dominant argumentative style, which I have selected at random:

As in Tunnel, however, this nondeontic reason [the awfulness of acting to bring about someone’s death] could not decisively outweigh your reason to do what would save several people’s lives. If Bridge is significantly different from Tunnel, as many people would believe, this difference could not, I believe, be that, since you would be killing me as a means, you would have a decisive non-deontic reason not to act in this way. This feature of this act might give you a decisive reason not to act in this way. But it could do that, I believe, only by making this act wrong. This decisive reason would have to be deontic. If that is true, the objection we are now considering fails.

Since passages such as this invite scrutiny of Parfit’s distinctions, concepts, and principles, and since they supply ample fodder for varying his preferred stories and challenging or confirming his judgments about them, the prediction I made earlier appears completely safe: On What Matters is a treasure trove for ethical theorists, looking to make their mark in the professional journals. Whether it can contribute to broader ethical discussions about the pressing problems that occupy people and their societies is, of course, a different matter.

III.
SOME OF THE chief anxieties about Parfit’s version of ethical theory are already voiced by the commentators whose essays open his second volume. One prominent theme in the commentaries is whether Parfit’s claim about the convergence of three independent traditions is surprising (and thus has the probative force he attributes to it). The critics point out, with considerable justice, that Parfit has carefully selected just those elements in the three ethical traditions that have some kinship with one another, ignoring more central features that would be far harder to reconcile. The points they raise are valuable for philosophers interested in the history of ethical theory, and particularly for those concerned with Kant’s writings on morality. Parfit replies to the historical concerns at some length, but spends far less time addressing two more fundamental objections raised by his commentators.

Yet a collapse of the “surprising convergence” would seem less problematic for the Triple Theory than these two further objections. The first of them concerns the goal of the project. Owing to his fondness for thinking of ethical theory as analogous to theories in areas of the sciences, Parfit often writes as if the goal of the enterprise is to produce a collection of principles that could be more or less mechanically applied to ethical decision-making. After the Triple Theory has been fully developed, when the three traditions have shaken hands on the mountain peak, there will be a new way of guiding our ethical life: sensitive judgment will give way to accurate calculation. But would that really be an improved, ultra-efficient way of guiding our ethical life? Would it not be, rather, something entirely different—something in which the value of sensitive judgment would have been lost? Ethical decisions owe part of their value to the person’s own activity of thinking through the problem, which often involves engaging with the situations and feelings of others. Judgment is not a matter of applying some formula that has been delivered by a correct and complete theory.

An alternative to Parfit’s way of thinking about ethics and ethical theory would take the point of the enterprise to be one of assembling ideas that can be used both in helping people to develop into more sensitive judges and in serving as resources on occasions of judgment. Perhaps there is no single peak. Perhaps, as Susan Wolf suggests in her commentary, there is only an indefinitely extending range. Parfit is much too brief in responding to her cogent suggestion.

THE SECOND OBJECTION concerns the method employed throughout On What Matters. Short schematic fictions—“puzzle cases”—are used as if they were analogues of experimental results that could be used to test putative theoretical hypotheses. One deep difficulty with this method is that, for all the words that Parfit expends on attempts to clarify his central concepts, particularly the notion of a reason, the concepts finally remain imprecise, and readers must constantly struggle to decide whether his assertions about the bearing of the evidence are justified. Even more importantly, the reactions he intends us to share are strikingly different from the kinds of reports that play a valuable role in the development of the sciences: whereas the standardization of observations and experimental findings is crucial to scientific objectivity, when people offer their judgments about puzzle cases in ethics there are absolutely no standards for when they are doing it well, no serious understanding of what they are doing or how, no sense of how their judgments might be distorted by prior commitment to some ethical principle—and thus no way of knowing whether their reports have the slightest evidential worth.

Consider the case that Parfit refers to as “Bridge,” a variant on a muchdiscussed scenario. In the canonical version, five people are bound to a track and threatened by the approach of a train. On the rail of the bridge over the track sits a fat man, whose heft would be sufficient to stop the train. Would it be right to push him from his perch onto the track below, thus using him as a buffer to protect the five? Of course, if you imagine yourself on the bridge faced with this choice, all sorts of awkward and practical questions arise. Would you be able to dislodge the fat man? (For the puzzle case to work, you have to be of lesser girth—otherwise you would have the option of sacrificing yourself.) If you pushed him, would he fall in a way that would halt the train? Is there some other way to prevent the deaths—a signal that can be given or a switch that can be thrown? Could you persuade the fat man to jump? Could you say, “Fat man, let us leap together”?

To avoid some of these questions, Parfit’s variant of the story stipulates a remotecontrol device that you can use to launch someone from the bridge on to the track. In this way he seeks to dodge or escape certain questions—but his modification introduces many others. How can you tell what will happen if you use whatever device you have? Could you stop the train simply by opening the trap, without anything falling through? Can you signal to the potential victim and arrange for some appropriate substitute object to fall through the trap? Are there other devices you should seek that would allow you to communicate directly with the driver, or to stop the train in less messy ways? Your response to any actual situation would depend on how you would answer or address questions such as these—on how you would cast around in attempting to avoid any death or injury (just as, in the original story, you would seek alternatives to the stark choice assigned to you). Parfit’s emendation of the canonical scenario is guided by no standard of objectivity for evoking reliable responses, and thus it generates further versions of the disease it is intended to cure.

You cannot respond to the imagined predicament without thinking hard, but hard thinking leads through a cloud of questions to a state of confusion. A few conditions are simply declared: the outcomes are known and the options limited. But since that sort of certainty and limitation is exceedingly remote from the circumstances in which we make our practical decisions, our judgmental capacities cannot be put to work in their normal ways. Readers are pitched into a fantasy world, remote from reality, in which our natural reactions are sharply curtailed by authorial fiat. When we are called on to render a verdict, the dominant feeling is a disruption of whatever skills we possess, and a corresponding distrust of anything we might say-often publicly visible when lecturers ask their audiences to respond to some puzzle case: only partisans of some particular theory answer confidently, while the rest sit in uncomfortable silence. The reader may even be left with a deep sense of unease that matters of life and death are to be judged on the basis of such cursory and rigged information. (Allen Wood makes similar points trenchantly in his contribution to Parfit’s book. This part of Wood’s critique goes unaddressed by Parfit.)

Parfit’s only defense of his use of puzzle cases occurs in passing, in a much earlier passage in which he proposes that thought-experiments are as valuable in ethics as they are in the sciences. The comparison prompts an obvious response—that many scientists think of thought-experiments as motivational rather than probative, as preludes to real experiments that will elicit genuine evidence. (It should also be noted that the great thoughtexperiments in the history of science occur in domains in which the questions can be precisely defined.) And matters are made even worse when the puzzle cases are used to interrogate the reasons that an imagined agent within the story might have for acting in a particular way. The vagueness of Parfit’s concept of a reason—a concept he takes to be indefinable—vitiates any serious attempt to survey the range of reasons someone has at his disposal. Even after the many claims about reasons Parfit makes, a sensitive reader should still wonder if those claims are justified. Moreover, his extensive discussion of issues about ethical truth and ethical knowledge renders our capacities for arriving at judgments, whether about individual situations or about general principles, so mysterious that the reader’s sense of hopeless floundering is further compounded.

After his lengthy attempt to scotch all naturalistic approaches to ethics, Parfit addresses the worry that admitting “non-natural facts” is to venture into an obscure and possibly incoherent metaphysics. His solution is that some truths (including ethical truths) are true in some “non-ontological sense,” and that “we form many true beliefs because these beliefs are intrinsically credible, or because we are aware of facts that give us reasons to have them.” In short, we possess an ability—Parfit thinks of it as shaped by natural selection, but it is probably better to view it as the product of natural selection and sociocultural learning—that can be exercised, in ways we do not understand at all, to yield a special sort of truth that we also do not understand at all.

It is hard to feel confident about the existence of such an ability, or that our judgment results from its proper exercise, especially when we are putting it to work on an artificial case in which our natural thoughts are constrained in many ways and when the verdict we are to provide concerns imprecisely formulated principles. Parfit’s best-developed attempt to defend his postulated ability is to draw on an analogy with mathematical knowledge. Yet many things mathematicians once took to be selfevident were later rejected by their successors, and principles now judged basic emerged from a complicated history of mathematical exploration. In mathematics, self-evidence is achieved, not given.

So we have not been given any good reason to think that the Triple Theory is the true ethical theory. While the traditions from which Parfit draws have supplied useful resources for ethical judgment, his versions of their central ideas are not especially precise, nor readily applicable, nor well-supported by the evidence that he offers. On What Matters does not contribute—perhaps it does not intend to contribute—to fostering ethical discussion and ethical practice in the broader world.

IV.
IS THERE A BETTER alternative? I believe there is, and it is a version of the Naturalism that Parfit so vigorously opposes.

Parfit is gripped by a particular picture of ethical knowledge, one in which people can discover ordinary kinds of facts by ordinary kinds of means, the sorts of methods used by ordinary observers and investigators, as well as by the most insightful researchers, methods that deliver information about mice and molecules, murder, monsoons, and mayonnaise. In his view, the task of understanding ethical knowledge is either that of building a bridge from these facts to ethical judgments or of finding some separate source for those judgments. After failing to find a bridge from facts to values, Parfit sets out on his quest for his (nebulous) source of ethical knowledge. Yet for at least a century, philosophers have known that this kind of picture of knowledge is mistaken. Human beings begin in the middle, with a mix of beliefs, and the proper topic concerns the grounds for a change of belief. People acquire, early in their lives, a complex collection of ideas about the natural world and about how they should think, feel, and act. As they grow, they change their minds, sometimes producing large collective transformations in the prevailing views about what is to be done.

According to a well-worn joke, an American traveling in Ireland spends a long time trying to find the remote village he aims to visit. At last he stops to ask one of the local inhabitants how to get there. And he is told: “Well, I shouldn’t start from here if I was you.” The philosophical predicament is often quite similar. Ethics might be better understood, and ethical life might be improved, if we began with the right questions.

One version of Naturalism starts by thinking of ethics not as the search for a single immutable all-serving principle, but rather as an entirely human endeavor, a project begun by our remote ancestors tens of thousands of years ago and continuing indefinitely into the future. There is no mountain to climb, no final compendium of ethical truths, but only a central human predicament, from which we escaped by learning—imperfectly—to regulate our own conduct. The philosophical study of this project must absorb the insights of various natural and human sciences, bits of evolutionary biology and primatology, of psychology and anthropology, of archaeology and history. (Naturalism should be elaborated broadly, recognizing the potential contributions of all rigorous forms of inquiry across the entire spectrum, from art history and anthropology to zoology; there is no need for Naturalists to lapse into the scientism of taking some particular area of physical science as fundamental.) Sensible conclusions cannot be reached by pitting imprecise principles against fanciful cases, but rather by looking, as carefully and as comprehensively as we can, at the details of ethical practice and ethical change.

Our ancestors once lived in small groups, mixed by age and sex, in the fashion of contemporary chimpanzees. To participate in this type of social life, they required some capacity for identifying and responding to the desires of the other members of the band, but the limitations of that capacity made their lives together tense and fragile. Self-regulation began as a social technology, directed at overcoming the limitations of our altruism. Rules for conduct, discussed within the group, came to govern human lives. Through a long period of time, probably at least fifty thousand years, different small societies engaged in social experiments. The ethical practices that exist today are the heirs of the most successful of these experiments.

Along the way many things happened. The initial framework of rules and motivating devices was probably very crude: the first commands were likely focused on the most prominent causes of social tension, giving rise to prescriptions for sharing scarce resources and proscriptions against initiating violence; band members were motivated to comply through their fear of punishment. Subsequent generations added more subtle ways of inducing conformity, recruiting emotions of solidarity, shame, and pride, feelings of respect and awe, often directed toward a powerful being viewed as the source of the group’s way of life. Attempts to resolve the challenges imposed by scarcity fostered a division of labor, out of which roles and institutions emerged. The extension of some protections to neighbors paved the way for an expansion of group size, and increased cooperation generated higher forms of altruism. The ethical framework familiar to us evolved gradually, through a series of small steps. The law codes that are among the earliest written documents testify to hundreds of generations of prior discussion. During recorded history ethical changes become perceptible. Although instances of ethical progress may be rare, it is hard to resist the thought that some of these modifications are progressive.

YET HOW CAN a naturalist approach make sense of a concept of ethical progress? Not by conceiving of it as the discovery of a prior and independent truth. Better to think of it as consisting in the solution of problems—as progress from, not progress to. Ethics begins as a social technology, aimed originally at making up for the limits of human altruism. Some prominent episodes in the recorded history of ethical practice take up versions of the original problem: when slavery is abolished, when women’s choices are expanded, when prejudices against certain forms of sexual expression are overcome, a prior situation in which there is a systematic failure to identify with the desires and the aspirations of other people is changed—a class of failures of altruism is resolved.

The changes come about not through recognition of some special ethical fact, hitherto unappreciated, but through the discovery of natural facts, about people, their capacities, sufferings, and aspirations, on the basis of which there are new possibilities for mutual engagement. Reformers come to see that desires that have been ignored or viewed as perverse are central to the lives of others, and through a more informed, inclusive, and sympathetic conversation, they learn how those desires can be satisfied without interfering with anyone’s fundamental aims.

But the identification and overcoming of our failures of altruism is not the only mode of ethical progress. Like other forms of technology, the ethical project is not limited to the problem out of which it arose. It generates new problems as it evolves. The “ethical truths” we arrive at are those principles introduced in progressive—that is, problemsolving—transitions, and retained in subsequent progressive changes: in William James’s happy phrase, “Truth happens to an idea.”

The great ethical theorists, on such an account, are those who supply resources for human decisions—collective human decisions—directed at problem-solving. Many of these thinkers have both reflected extensively on the practices of the societies in which they find themselves and have been deeply immersed in the theoretical ideas of their predecessors. (In our own times, John Rawls is an outstanding example.) Whatever their intentions, they offer no final theory, no “supreme principle of morality.” Moreover, although they facilitate conversation, serving as philosophical midwives, they cannot claim any special expertise in discovering ethical truth. Just as ethical practice began in negotiation within a small group, so, at its best, it continues by involving many—ideally all—human perspectives, under conditions in which each strives to accommodate the interests of all others.

WE SHOULD DISPENSE with the myth of the sage, the guru, the teacher, and the ethical expert, which has often distorted the ethical project. The image of the moral philosopher as expert is a latecomer: in human history, by far the most prominent claims to special ethical expertise have been those of religious teachers, who have sometimes, although not always, used their alleged access to the supernatural to inscribe their own prejudices into a group’s ethical code. But philosophers who reject that version of the story fall into a rival fable, according to which they are the people who have insight into pre-existent ethical truth, and they are the pioneers who climb the mountain. For all its intellectual perseverance and academic penetration, On What Matters remains trapped in the acceptance of this latter myth.

Whether the approach I have sketched is ultimately satisfactory (and it probably is not), I am convinced that its kind of Naturalism, and the questions that it poses, offer an important corrective to contemporary fashions in academic ethics. Although he does not construe Naturalism in terms of an interdisciplinary perspective on the ethical project, Parfit regards the forms of Naturalism he considers as a serious threat. On several occasions he remarks that, if Naturalism is true, then much of his life will have been wasted. My last disagreement with him concerns this wrenching judgment.

If Naturalism is true, then many of Parfit’s claims are indeed wrong and his perspective is indeed askew. Does it follow that his efforts (and consequently much of his life) have been wasted? I do not think so. Almost all those who have engaged in any form of inquiry have been wrong and misguided. That is our predicament: fallible investigators start from the conclusions of their fallible predecessors. Yet even the dedicated mathematical astronomers of the late Middle Ages who explored the complicated details of the equant point in Ptolemaic theory contributed to the advancement of the science, by supplying standards by which more promising post-Copernican systems might be judged, and by introducing possibilities and options into future debates. On What Matters belongs with such achievements. It stands as a grand and dedicated attempt to elaborate a fundamentally misguided perspective. Its diligence and its honesty command respect. Perhaps these real virtues will set standards for very different ventures in academic ethics, Naturalist or otherwise—for a return to the tradition of attempts to understand and improve everyday judgment, and to provide resources for people and policymakers everywhere. In the end, that is what matters.

Philip Kitcher is John Dewey Professor of Philosophy at Columbia University and the author, most recently, of The Ethical Project (Harvard University Press). This article appeared in the February 2, 2012, issue of the magazine.